<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    body{
        margin:0px;
        padding:0px;
        height: 100vh;
        display: flex;
        justify-content: center;
        align-items: center;
        background:#000;
    }
    .square{
        width: 100px;
        height: 100px;
        background: #fff;
        box-shadow: 0px 0px 40px #0fff;
        animation: spin 1s infinite;
    }
    @keyframes spin{
        0%, 100%{
            
            transform: rotate(90deg);
        }
            
        50%{
            border-radius: 50%;
            transform: rotate(180deg);
             
        }
        
    }
    .loading_text{
        color:#fff;
        text-shadow: 0px 0px 40px #0fff;
        text-align: center;
        font-weight: bold;
        font-size:20px;
        margin-top:40px;
        font-family: Arial, Helvetica, sans-serif;
    }

.loading_text span{
    opacity: 0;
    font-size: 20px;
}

.loading_text span.first{
    animation: first_loader_dot 2s infinite;
}
.loading_text span.second{
    animation: second_loader_dot 2s infinite;
}
.loading_text span.third{
    animation: third_loader_dot 2s infinite;
}

@keyframes first_loader_dot {
    0%{
        opacity: 0;
    }
    15%{        
        opacity: 0;
    }
    25%{    
        opacity: 1;
    }
    100%{
        opacity: 1;
    }
}
@keyframes second_loader_dot {
    0%{
        opacity: 0;
    }
    25%{        
        opacity: 0;
    }
    50%{    
        opacity: 1;
    }
    100%{
        opacity: 1;
    }
}
@keyframes third_loader_dot {
    0%{
        opacity: 0;
    }
    50%{        
        opacity: 0;
    }
    75%{    
        opacity: 1;
    }
    100%{
        opacity: 1;
    }
}
</style>

<body>
   <div class="loader">
    <div class="square"></div>
    <div class="loading_text">
        Loading 
        <span class="first">.</span>
        <span class="second">.</span>
        <span class="third">.</span>
    </div>
   </div>
</body>
</html>